Wafer and the manufacturing and reclaiming methods thereof

1. A method of manufacturing a non-productive wafer, comprising: providing a semiconductor substrate; simultaneously forming a first protective layer on a first surface of said semiconductor substrate, and a second protective layer on a second surface of said semiconductor substrate; forming a polysilicon layer on said semiconductor substrate; oxidizing said polysilicon layer so as to form an oxide layer; and removing said oxide layer; wherein said non-productive wafer is used to improve the quality of a deposition process of polysilicon on one or more productive wafers by subjecting the non-productive wafer to the polysilicon deposition process performed on the productive wafers, wherein the protective layer protects the semiconductor substrate from damage during removal of said oxide layer from the non-productive substrate to reclaim the non-productive wafer, and wherein said protective layer is a silicon nitride layer formed by a chemical vapor deposition process, said chemical vapor deposition process employing SiH 2 Cl 2 gas or NH 3 gas.

2. A method for reclaiming a non-productive wafer, comprising: simultaneously forming a first silicon nitride layer over a first surface of a substrate and a second silicon nitride layer over a second surface over a second surface of the substrate; forming a polysilicon layer over the first silicon nitride layer; oxidizing the polysilicon layer so as to form an oxide layer; and removing the oxide layer.

3. The method of claim 2 , wherein forming the first silicon nitride layer comprises forming the first silicon nitride layer continuously extending from an edge of the substrate to an opposing edge of the substrate.

4. The method of claim 2 , wherein forming the polysilicon layer comprises forming the polysilicon layer continuously extending from an edge of the substrate to an opposing edge of the substrate.

5. The method of claim 2 , wherein forming the first silicon nitride layer comprises forming the second silicon nitride layer continuously extending from an edge of the substrate to an opposing edge of the substrate.

6. The method of claim 2 , wherein oxidizing the polysilicon layer includes a thermal oxidation step.

7. The method of claim 2 , wherein removing the oxide layer is a wet etch process.

8. The method of claim 7 , wherein the wet etch process uses hydrogen fluoride (HF).

9. The method of claim 2 , wherein the substrate is a control wafer or a dummy wafer.

10. The method of claim 2 , wherein forming the first silicon nitride layer uses SiH 2 Cl 2 gas or NH 3 gas.

11. The method of claim 2 further comprising removing the first silicon nitride layer after removing the oxide layer.

12. The method of claim 2 wherein forming the polysilicon layer is carried out in a furnace having productive wafers and non-productive wafers.

13. The method of claim 2 further comprising using the non-productive wafer to improve a quality of a polysilicon deposition process, the polysilicon deposition process being used in forming the polysilicon layer.

14. The method of claim 13 further comprising using a thickness of the polysilicon layer to control stability of the polysilicon deposition process.

15. The method of claim 1 , wherein the first protective layer and the second protective layer are configured to protect the semiconductor substrate free from losing thickness.

16. The method of claim 2 , wherein the first silicon nitride layer and the second silicon nitride layer are configured to protect the substrate free from losing thickness.